Monitoring of the residues of some pesticides in mulberry leaves and their safety evaluation

뽕잎중 잔류농약의 monitoring 및 안전성 평가

In order to evaluate the safety of mulberry leaves for sericultural purpose to the contamination by pesticide residues, the analyses of dichlorvos, acephate, phenthoate, pyrazophos, deltamethrin, and cypermethrin were done for 24 samples collected in spring and fall over two consecutive years (1996 and 1997), each, from 8 provinces across the country, by selecting three representative farmhouses in each province. In spring samples of 1996, the residual amounts of dichlorvos, acephate, and phenthoate were $0.018{\sim}0.032$, $0.013{\sim}0.072$, and 0.051 ppm, respectively, whereas, pyrazophos was not detected, and the detection frequencies were 29, 58, and 4%, respectively. In fall samples, on the other hand, those of the above pesticides were $0.012{\sim}0.048$, $0.020{\sim}0.156$, and $0.018{\sim}0.050$ ppm, respectively, and pyrazophos was not detected either and the detection frequencies were 42, 17, and 13%, respectively. While in spring samples of 1997, the residual amounts of dichlorvos, acephate, and cypermethrin were $0.014{\sim}0.064$, $0.033{\sim}0.061$, and $0.019{\sim}0.068$ ppm, respectively, and deltamethrin was not detected. The detection frequencies were 75, 13, and 8%, respectively. In fall samples, on the other hand, those of the above pesticides were $0.013{\sim}0.062$, 0.015, and $0.009{\sim}0.013$ ppm, respectively, and deltamethrin was not detected either. The detection frequencies were 88, 4, and 17%, respectively. Almost all of the samples turned out to be non-toxic to silkworms, except that one sample (No. 10, spring 1997) contaminated by a high concentration of cypermethrin (0.068 ppm) was judged to do harm to silkworms. In the GC analyses, the selection of columns, the change in column temperature, and the use of MSD made the separation and identification of the vague compounds possible.

농약에 의한 오염가능성이 있는 뽕잎의 안전성을 평가하기 위하여 뽕나무에 등록되어 있는 유기인계 살충제 dichlorvos, acephate, phenthoate와 유기인계 살균제 pyrazophos, 그리고 뽕나무에 등록되어 있지 않지만 인근 포장으로부터 비산오염될 가능성이 있는 pyrethroid계 살충제 deltamethrin과 cypermethrin에 대하여 2년간 그 잔류량을 분석하였다. 1996년의 봄시료의 일부에서 검출된 dichlorvos, acephate 및 phenthoate의 잔류량이 각각 $0.018{\sim}0.032$, $0.013{\sim}0.072$, 및 0.051 ppm이었고, pyrazophos는 검출되지 않았으며, 검출빈도는 각각 29, 58 및 4%이었다. 반면 가을시료에서는 dichlorvos, acephate, 및 phenthoate의 잔류량이 각각 $0.012{\sim}0.048$, $0.020{\sim}0.156$, 및 $0.018{\sim}0.050$ ppm이었고, pyrazophos는 역시 검출되지 않았으며, 그 검출빈도는 각각 42, 17 및 13%이었다. 1997년의 봄시료의 일부에서 검출된 dichlouos, acephate 및 cypermethrin 잔류량이 각각 $0.014{\sim}0.064$, $0.033{\sim}0.061$, 및 $0.019{\sim}0.068$ ppm이었고, deltamethrin은 검출되지 않았으며, 검출빈도는 각각 75, 13 및 8%이었다. 반면 가을시료의 일부에서는 dichlorvos, acephate, 및 cypermethrin의 잔류량이 각각 $0.013{\sim}0.062$, 0.015, 및 $0.009{\sim}0.013$ ppm이었고, deltamethrin은 검출되지 않았으며, 그 검출빈도는 각각 88, 4 및 17%이었다. Cypermethrin이 고농도 (0.068 ppm)로 검출된 뽕잎시료 (No. 10, 1997 봄)를 제외한 대부분의 시료는 누에에 무해할 것으로 판단되었다. 또한 phenthoate의 잔류분석에서는 GC column의 적절한 선택과 온도의 조절을 통하여 분리 및 확인이 애매한 화합물들을 확실하게 구분할 수 있었다.